The rapid diffusion of Wireless Local Area Network (WLAN) access and the increasing demand for WLAN coverage is driving the installation of a very large number of Access Points (AP). The most common WLAN technology is described in the Institute of Electrical and Electronics Engineers IEEE 802.11 family of industry specifications, such as specifications for IEEE 802.11b, IEEE 802.11g and IEEE 802.11a. A number of different 802.11 task groups are involved in developing specifications relating to improvements to the existing 802.11 technology. The IEEE 802.11 n task group has developed a High Throughput (HT) draft specification, entitled “Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: Enhancements for Higher Throughput,” IEEE 802.11n.D0.01, January 2006.
The 802.11n HT draft specification has proposed the use of a Power Save Multi Poll (PSMP) management frame, which is a MAC control frame that may be used by an AP to provide a data transmission schedule (e.g., time and duration for uplink and/or downlink transmissions) to one or more PSMP receiver nodes. However, the 802.11n PSMP frame provides inadequate support for multicast data transmissions.